light bike vs. body weight

I was riding downtown with a couple friends and of course we were bombing around trying to race to certain destinations. I kept winning every race and they would always say.. "well your bike is so light".

I was riding a fixed mb track which roughly weighs about 20lbs... They were both riding sub 30lb road bikes.
I weigh in at 228lbs at 5'11. Both the friends I was racing were under 180 and around the same height. Does it matter that Im riding a lighter bike.
What I want to know is, does it matter how light ur bike weighs for performance when you are heavy like me.

I mean, isnt the same difference of riding a 30lb to 20lb bike just the same as losing 10-15 lbs? I guess Im way off here but I feel like it could be the same as carrying that extra weight in your backpack.

You are just more cycling fit, yes you may be bigger but that means nothing if your 180lb friends do not have same bike fitness, or you may just be a good sprinter. Bike weight means crap if the engine is no good.

Best thing about cycling is when I'm at work I'm thinking of cycling, when I'm cycling I'm thinking about cycling.

I would say that's a bad choice of words. He could be a better sprinter, that's one thing. But after 40 miles, his buds might have made menudo out of him. Then who would be in better cycling fitness from mile 41-100?

Some riders are better sprinters, some are better long distance riders, some better climbers, some better TT riders.

I'd say you were maybe a better sprinter!...But remember, pound for pound, they're carrying a bigger loads far as ratio and proportions.

Your buds at 180 lbs carrying a 30 lb bike would be equaled by your carrying a 38 lb bike.

That's the sort of, if a 200 lb man benchpress 500 lbs, how much should a man of 120 lbs be able to benchpress for a man of his bodyweight to equal the other dude.

200 man 120 man
------- . ------- ..................Ratio and porportions, this times that equals this divided by that
500 lbs X

500 X 120 divided by 200 equals 300.............The 120 lb man would have to benchpress 300 lbs to be equally as strong as the 200 lb man pound for pound.

So to be equal, the bigger rider should have been riding a 38 lb bike to show he was equally as strong on the bike. Pound for pound!...so yes,you had an advantage at your weightwith a lighter bike!

ok I get ur points.. but lets just say that I was holding an extra 10lbs in my backpack and they werent holding anything.. would that make any difference.. or would it only matter if that weight was attached to the bike.

I think what matters when sprinting or climbing is power to weight ratio. As Clydes I'm told we are at some natural disadvantage... and watching little waifs climb, I must say it appears there is something to that.

So... to your question, assuming the riders weight is mostly muscles and some significant fraction of those muscles are being used to power the bike, I would say taking weight of the bike or out of the back pack counts more than the rider losing weight... As spiffy as a new super duper ride may be, it's really nothin' but dead weight until you pedal it.. so less is always better.

Of course removing bits of rider that aren't helping power the machine is just as helpful. I'm thinking of removing a few fingers and toes and perhaps shaving my head.

Last edited by Herbie53; 10-28-09 at 09:21 PM.

"Today me will live in the moment, unless it's unpleasant, then me will eat cookie." -Cookie Monster

Weight that you move up and down (legs, shoes) pedaling is worse than weight that just sits on the bike. If you are standing to pedal, then a backpack could be worse than the same weight on a bike rack or the bike itself.

Heavy has an advantage going downhill. Light has an advantage climbing.

At higher speeds or in wind consider drag and aerodynamics. A big profile is slower than a small profile.

On my bike (a cheap hybrid) I get about 1-2 mph faster on flats after loosing 21 kg(that's about 44 pounds) from 120kg to 99kg. On the other hand I am a lot faster on climbs. I will post again in 3-4 months when I (hopefully) get at my normal weight(81 kg).
I do think that since you are already carrying 5-10kg in excess weight you really should not pay 2000$ more for a lighter bike. On the contrary heavier is better (already wrote this on the MTB vs. road thread) if you want to loose weight.
If you are into competitions of course you need a light bike but I think that most guys on this forum need to loose weight first and then get into racing(I know there are exceptions).

The application of the ride to the bike is what is really important, IMO. Most light bikes are designed and built for the rider to ride quick and fast. The bike has to be nimble, and the rider has to be able to accelerate and maintain speeds for a longer period of time. For this application, the weight of the bike top to bottom is really important. You do have to be conscious that a good deal of the weight for a clyde rider is on the top of the bike, so your center of gravity moves up, affecting the handling of the bike at higher speeds. If you are really interested in longer rides, however, light weight becomes less of a factor to comfort. You then want to remain on the saddle for longer periods of time, and you want to use your legs in a more efficient manner for this application that does not involve spurts of acceleration. For longer rides, comfort is everything... not necessarily weight.